The present invention relates to a paper cutting device for a printer, ticket vendor and others.
As a conventional paper cutting device, there is known a device in which a movable cutter having a disc shape is rolled on a straight fixed cutter so as to cut a paper sheet.
FIGS. 16 and 17 show the conventional paper cutting device. An elongated fixed cutter 102 is in a frame 101, and a movable cutter disc 103 is rotatably supported in a cutter carrier 104 and mounted on the fixed cutter 102. The cutter carrier 104 is slidably mounted on a carrier feed shaft 105 having a feeding spiral groove 105a and a returning reverse spiral groove 105b. 
The underside of the cutter carrier 104 contacts with an end of a detector lever 107 at the illustrated home position. The other end of the detector lever 107 is connected with a detector 106. The detector 106 generates a signal which is applied to a control circuit (not shown) for informing that the cutter carrier 104 is located at the home position.
Referring to FIG. 17, a gear 112 secured to the left end of the feed shaft 105 is connected to an output shaft 108a of a carrier feeding motor 108 through gears 111, 110 and a gear 109 secured to the output shaft 108a. 
When a paper sheet is cut, the paper sheet is put on the fixed cutter 102, and the motor 108 is operated to rotate the carrier feed shaft 105. At the home position, the cutter carrier 104 engages with the feeding groove 105a. Consequently, the cutter carrier 104 is fed to the right to rotate the movable cutter disc 103. Thus the paper sheet is cut by the movable cutter disc 103 and the fixed cutter 102.
When the cutter carrier 104 arrives the right end, the cutter carrier 104 is engaged with the returning groove 105b. Thus, the cutter carrier 104 is fed to the left. When the cutter carrier 104 arrives the home position, the motor 108 is stopped by the operation of the control circuit dependent on the operation of the detector lever 107 and the detector 106.
In the conventional device, the cutter carrier 104 slides on the feeding groove 105a or the returning groove 105b of the feeding shaft 105 during the cutting operation. Consequently, there is large frictional resistance between the cutter carrier 104 and the feeding shaft 105, thereby increasing the load on the carrier feeding motor 108 and generating large noises. In addition, it is necessary to perform a number of processing steps to manufacture the feeding groove and the returning groove of the feeding shaft 105, which causes the manufacturing cost to increase.
An object of the present invention is to provide a paper cutting device which is small in frictional resistance and in noise and which may be manufactured at a low cost.
According to the present invention, there is provided a paper cutting device comprising a frame, a straight fixed cutter mounted on the frame, a movable cutting carrier slidably supported on the frame to be moved along the fixed cutter, a movable cutter having a disc shape and rotatably mounted on the carrier, and contacted with the fixed cutter at a side surface thereof, a movable cutter rotating roller rotatably mounted on the movable cutter carrier and resiliently contacted with the movable cutter at a side surface thereof and with the fixed cutter, a carrier feeding endless belt provided in the frame along the fixed cutter, a carrier connecting member operatively connecting the movable cutter carrier with the endless belt, a belt driving motor, a power transmitting device for transmitting the power of the motor to the endless belt for driving the endless belt, whereby the movable cutter carrier is moved by the endless belt, and the movable cutter is rotated along the fixed cutter so as to cut a paper sheet mounted on the fixed cutter.
The device further comprises a shaft mounted on the movable cutter carrier, a movable cutter cylindrical holder mounted on the shaft, and a holding member mounted on the movable cutter cylindrical holder, the movable cutter rotating roller being mounted on the holding member.
A fixing projection is formed on a peripheral portion of the belt for connecting the carrier with the belt.
The movable cutter rotating roller urges the movable cutter to a flange formed on the movable cutter cylindrical holder to hold the movable cutter.
The carrier connecting member has a cylindrical projection slidably engaged with a vertical elongated hole formed in the movable cutter carrier, and engaged with the fixing projection on the belt.
A spring is provided between an inside wall of the carrier and the movable cutter cylindrical holder for pressing the movable cutter against the fixed cutter.
These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.